Intravenous perfluorocarbon after onset of decompression sickness decreases mortality in 20-kg swine.

INTRODUCTION

Decompression sickness (DCS) occurs when bubbles form due to pressure decreases with severity ranging from trivial to fatal. Standard treatment requires a hyperbaric chamber, not likely to be available at remote sites or during a disabled submarine escape or rescue. Alternative (non-recompressive) treatments are needed. Intravenous administration of emulsified perfluorocarbons (PFCs) enhances oxygen delivery to, and inert gas removal from, tissues. Swine studies show PFCs administered with supplemental oxygen before symptom onset can decrease DCS incidence. We used a swine model to test whether PFC plus supplemental oxygen could improve outcome when infused after DCS symptom onset.

METHODS

After rapid decompression from 31 min at 200 fsw (7.06 ATA) animals were observed for signs of DCS. Upon DCS onset animals received 100% 02 and were randomized to receive either saline or PFC. Oxygen administration was continued for 1 h and the primary outcomes of mortality and/or abnormal gait were noted 24 h after surfacing.

RESULTS

PFC significantly improved survival, with 18/25 (72%) PFC treated animals and 13/29 (45%) saline treated animals alive at 24 h post-exposure. Objective measures of stance/gait trended toward improvement; spinal cord lesions correlated with severity of stance/gait abnormalities.

CONCLUSION

PFC administered after DCS onset improved survival in this 20-kg swine model. Further study into the mechanisms of benefit and delayed DCS therapy are warranted.